Amir Hossein Barjini - Sharif University of Technology, Tehran
Mohammad Dastranj - Sharif University of Technology, Tehran
Hassan Sayyaadi - Sharif University of Technology, Tehran

In the preceding years, mobile robots have attracted the attention of researchers due to their various applications in industry, agriculture, rescue operations, etc. Nowadays, many researchers have concentrated on using Mecanum wheels for mobile robots because of their superior mobility. Previous papers have modeled mobile robots using constant-mass assumption; however, variable-mass mobile robots have copious applications, such as spraying in agriculture, painting traffic signs on streets and even fuel consumption in robots that run on fossil fuels. Accurate modeling, path-planning and control are among the primary challenges in this field. In this paper, after considering the literature review, a variable-mass four-Mecanum-wheel mobile robot is modeled. For path planning, the minimum jerk trajectory design method is used for deriving the desired positions and rotations. For trajectory tracking, a nonlinear sliding mode controller is used. The results have shown that the proposed controller is able to control the system properly and could track the desired positions and rotations.

Mecanum wheel, Variable-mass modeling, Mobile robot, Sliding mode controller, Trajectory tracking